At the U.S. Supreme Court's arguments Wednesday in a major abortion rights challenge from Louisiana, the likely key to how the case is resolved—Chief Justice John Roberts Jr.—appeared focused on how closely the justices must follow their 2016 decision striking down a nearly identical law.

Roberts voted in dissent in the 2016 case, Whole Woman's Health v. Hellerstedt, which struck down a Texas requirement that abortion physicians have hospital admitting privileges within 30 miles of their clinics. The high court majority ruled that the hospital admitting privileges requirement had no medical benefits and thus unduly burdened a woman's access to abortion.

Roberts on Wednesday in the Louisiana case, June Medical Services v. Russo, asked the same questions of both the clinic's counsel and Louisiana's lawyer: Is the inquiry into whether there are any medical benefits the same in each state?

Justice Brett Kavanaugh, who joined the court in late 2018, took a similar tack, asking Julie Rikelman of the Center for Reproductive Rights, representing the clinic June Medical Services: "Are you saying hospital admitting privileges laws are always unconstitutional?"

Rikelman answered that while the burdens of these laws may vary state by state, the medical consensus is unanimous that they provide no medical benefits, a central holding in the Whole Woman's Health opinion.

A major difference between the 2016 case and Wednesday's case is the composition of the Supreme Court. Justice Anthony Kennedy was key to the 5-3 majority in 2016, but he has since retired. Trump appointees Justices Neil Gorsuch and Kavanaugh are now on the bench.

The Trump administration's Justice Department told the Supreme Court in a brief that the department supported overturning the 2016 decision in Whole Woman's Health.

Rikelman opened her argument by telling the justices, "This case is about respect for the court's precedents." However, she quickly ran into a buzzsaw of questions from Justice Samuel Alito Jr. on another significant issue in the case: whether abortion physicians and clinics on their own can sue states on behalf of their patients. A ruling that says only pregnant women can sue could widely reduce complaints challenging state regulatory schemes, reproductive rights advocates contend.

Alito repeatedly challenged Rikelman's interpretation of the federal trial court's findings that Louisiana had waived a challenge to the clinic physicians' standing to sue on behalf of pregnant women. He called her reply that there was standing even if a conflict existed between the interests of the physicians and their patients "amazing."

But Rikelman insisted that the Supreme Court had approved third-party standing in abortion cases and in other contexts for decades and for good reasons. Justice Stephen Breyer noted that such standing had been approved by the court in at least eight past abortion cases.

Roberts did not ask questions confronting whether physicians and clinics can sue on behalf of their patients.

Justices Ruth Bader Ginsburg, Sonia Sotomayor and Elena Kagan challenged Louisiana Solicitor General Elizabeth Murrill on the state's justification for the 30-mile admitting requirement. The justices said most women, if they experience a rare abortion complication, would be at home and likely to turn to their local hospital for help.

Murrill claimed the abortion physicians in the case "sabotaged" their own hospital applications and that the clinics did not keep good records of the number of times they were forced to send a woman to a hospital because of complications from the procedure.

Louisiana's admitting privileges requirement was enacted in 2014 and was modeled after the Texas law that the justices struck down in 2016. The law requires doctors to have "active admitting privileges" at a hospital within 30 miles of the facility performing abortions. Doctors must be members of the hospital medical staff with the ability to admit patients and care for them. The law imposes fines, license revocation, imprisonment and civil liability for violations.

Soon after the law's enactment and before it took effect, two abortion physicians sued the state arguing that the law violated the Fourteenth Amendment because it unduly burdened women's access to abortion and their due process rights.

A federal district court temporarily blocked the law's penalties for violations and subsequently held a six-day bench trial on the motion for a preliminary injunction. The court in 2016 granted the physicians' motion. In June of that year, the Supreme Court in a 5-3 decision struck down the Texas law.

The Louisiana ruling was appealed to the U.S. Court of Appeals for the Fifth Circuit, which reversed the trial court in a 2-1 panel ruling. The majority, distinguishing the state's law from the Texas law, said Louisiana's law provided a "minimal benefit" to women's health and "insubstantial burdens" on their access to abortion. Some of the abortion physicians, it said, did not try hard enough to obtain admitting privileges. A closely divided en banc court denied a request for rehearing.

In February 2019, the Supreme Court, in a 5-4 order, granted an application by the doctors and the clinic for an emergency stay pending the filing of their petition for review. Justices Clarence Thomas, Samuel Alito Jr., Neil Gorsuch and Brett Kavanaugh, who wrote separately, dissented. Roberts sided with the court's liberal colleagues in blocking the law from taking effect.